Devices and systems for emptying canisters filled with a substance, in particular a fluid, are known in practice in various forms. These known devices often incorporate a suction lance that is inserted into the canister and that is pointing from an opening of the canister into the canister for drawing the substance out when coupled to a suction device. The canisters are usually not emptied by way of the suction lances so as to be free of residue, hence a residual quantity of substance, in particular fluid, remains in the container. For the disposal of canisters that are filled with dangerous or harmful substances for example it is a desirable aim to reduce the amount of substance that is left in the canister to a minimum. Moreover, it is desirable to reduce the risk of an unintended contact of a person handling the empty canisters with the substance left in the canister in order to reduce and avoid any health risks.